Quatech INTERBUS S manual Further information, Cenelec IEC

Application in Explosive Environments • 5

Classification meeting CENELEC and IEC

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Identifi-	CENELEC	IEC	Explanation	Application
cation	standard	standard
EEx o	EN 50 015	IEC 79-6	Oil encapsulation	Zone 1 + 2
EEx p	EN 50 016	IEC 79-2	Overpressure	Zone 1 + 2
			encapsulation
EEx q	EN 50 017	IEC 79-5	Sand encapsulation	Zone 1 + 2
EEx d	EN 50 018	IEC 79-1	Pressure resistant	Zone 1 + 2
			encapsulation
EEx e	EN 50 019	IEC 79-7	Increased safety	Zone 1	+ 2
EEx m	EN 50 028	IEC 79-18	Cast encapsulation	Zone 1	+ 2
EEx i	EN 50 020 (unit)	IEC 79-11	Intrinsic safety	Zone 0	+ 1 + 2
	EN 50 039 (system)
EEx n	EN 50 021	IEC 79-15	Electrical components	Zone 2
			for zone 2 (see below)

Ignition protection “n“ describes exclusively the use of explosion protected electrical components in zone 2. This zone encompasses areas where explosive atmospheres can only be expected to occur rarely or short-term. It represents the transition between the area of zone 1, which requires an explosion protection and safe area in which for instance welding is allowed at any time.

Regulations covering these electrical components are being prepared on a world-wide scale. The standard EN 50 021 allows electrical component manufacturers to obtain certificates from the corresponding authorities for instance KEMA in the Netherlands or the PTB in Germany, certifying that the tested components meet the above mentioned standards draft.

Type “n” ignition protection additionally requires electrical components to be marked , with the following extended identification:

•A – non spark generating (function modules without relay /without switches)

•AC – spark generating, contacts protected by seals (function modules with relays / without switches)

•L – limited energy (function modules with switch)

Further information

For more detailed information please refer to the national and/or international standards, directives and regulations!

WAGO-I/O-SYSTEM 750 Modular I/O-System